A Lexington Park man died Saturday after a U.S. Navy helicopter’s crew found and carried him from the Chesapeake Bay, authorities report, in the aftermath of a boating accident that also claimed the life of his fiancee’s stepfather.

The helicopter brought 43-year-old David Fletcher to MedStar St. Mary’s Hospital in Leonardtown, where an ambulance crew arrived with 55-year-old David Chase, also of Lexington Park.

A spokesperson for the Maryland state medical examiner’s office in Baltimore said Monday that autopsies determined that the accidental deaths of Fletcher and Chase were caused by drowning, complicated by coronary problems. “They both had heart disease,” the medical examiner’s spokesperson said.

Four survivors also were rescued during the response by Ridge volunteer firefighters and other emergency responders who rushed by boat to the scene. Those passengers were identified this week by Maryland Natural Resources Police as 38-year-old Katrina Washington, Fletcher’s fiancee, along with Richard Stone, a 42-year-old Scotland resident who owned the capsized boat, his wife, Mary Hobbs, 44, and Brady Hobbs, a 14-year-old son.

At about 8:30 a.m. Saturday, according to the U.S. Coast Guard, a local charter boat captain was contacted by a sister of a passenger on the 25-foot vessel, after the passenger called her to say that the boat was taking on water. Radio monitors heard the charter captain asking for assistance to find the overturned boat, and boat crews from the Coast Guard station in St. Inigoes, natural resources police and St. Mary’s fire and rescue volunteers from Ridge and 2nd District began responding to the scene two miles south of Point Lookout State Park.

Waves of three to five feet were in that area on Saturday morning, the first day of rockfish season, according to natural resources police. Sgt. Brian K. Albert said Tuesday that the boat’s bilge pump will be tested during the ongoing investigation, but that there were no indications of any problems with its motor, and that the conditions that morning remain a likely key factor in the accident.

“We’re thinking the rough seas,” Albert said.

Petty Officer David Marin of the Coast Guard said Tuesday that of the boat’s six passengers, “Some of them had life preservers on, [but] not everybody.”

Fletcher and Washington had gone out fishing with Stone one time before Saturday’s trip, family members said Sunday outside the couple’s home in the Patuxent Park neighborhood.

An uncle called their oldest son from the hospital, where Washington, Stone and Brady Hobbs were being treated for hypothermia, but it was Washington who later got home to tell the younger children that their father and the man they regarded as their grandfather had died in the accident.

Chase was making his first trip out on the boat, Davondre Fletcher, 12, said on Sunday.

“They took him to shore [during the rescue], and he had a slight pulse. It just stopped,” the grandson said. “He shouldn’t have died that way. He should have died old, not drowned.”

Chase and the four survivors were in the water for about an hour, his family members said, but David Fletcher was in the water for about 90 minutes before the helicopter crew spotted him.

“Dad’s in a happy place,” Kabari Brooks, 16, another of Fletcher’s sons, said Sunday, “but that’s not the right way.”

Dahjanee Fletcher, 15, said her father also enjoyed motor sports in Budds Creek, when he wasn’t fishing and in the company of the other people he was with on Saturday.